Rabin Changmai — low quality of service and customer support

I m a owner of your layland tipper 1618 (Veh no-as-07ac4996). It was purchased in the month of march 2018. From the starting month vehicle" take air and unable to run ” i allready complained it in my area engineer and also your authorised service center (R r motors, north lakhimpur). But they are fail to completly diagnosed and finished this problem and also take many days due that i m havily lost in my business site.
So requested your company to give me a right way to solve this problem.
Regard's
Mr rabin changmai (Owner)
C/no -[protected]